Interestingly, I listened to a radio broadcast last week about an American cook who was showing the public how to fry chicken on a TV programme. The presenter standind alongside her asked her how she knew when the chicken was cooked and she replied you listen to the sound of the grease. The presenter apparently gave her a look that said "You're taking the ****!" So for the radio programme, they recorded the sound of fried chicken cooking and asked her to identify the sounds during the various stages. There was a distinct difference in the frequency of the noise it made in the 3 samples they took and when asked to identify each noise, she gave the correct reply, however she admited there were probably other factors such as smell and eyesight that added to her knowing knowing when it was perfectly done.